The temperature of a liquid cooled internal combustion engine is typically controlled by a liquid coolant circulated through the engine and a radiator. Currently, an attempt to control engine temperature is done through a system for controlling the temperature of the liquid coolant, typically by controlling the rate at which it circulates. Such systems are not sufficient when operating under extreme hot or cold conditions, i.e., the liquid coolant may be too cold or get too hot. If the coolant is too cold, the engine may run rough or stall and if the coolant is too hot, the engine may overheat and be damaged. Overheating can occur on very hot summer days or when the motor vehicle is driven hard or in heavy traffic necessitating frequent stops and starts. Overheating is also likely when the air conditioner is running adding additional load on the engine. Overcooling can occur under extremely cold driving conditions.
As previously taught, liquid cooled engines can be cooled by running the heater in the passenger compartment, wherein the heat generated by the heater comes from the coolant, a portion of which is routed through a heater core for warming the passenger compartment. This reduces the temperature of the circulating liquid coolant in hot weather at the expense of the passengers' comfort, particularly in hot summer conditions. An attempt to provide an alternative cooling of the engine has been to direct some of the artificially cooled air back at the radiator.
There exist other aftermarket products for heating or cooling a liquid cooled engine. There are electrical heaters for heating the coolant and devices for cooling the radiator. There is a system for directing a side stream of air from a cool air conditioner onto the radiator and another system for directing a stream of heated or cooled air from an auxiliary air tempering unit onto the radiator. While there has been some improvement in the field, there remains a need to improve heating/cooling systems in liquid cooled engines.